Plant Eco 2/19/19

“Cumulative percent cover”

1. How does species percent cover and diversity correlate with time since restoration?

Hypothesis: We will see increased exotic species percent cover and diversity with increased time since restoration.

1a. Total percent cover of exotics over time since restoration

Results: Increase in total exotic percent cover over time, driven by WT1, WT2, PH1, & especially RT.

1b. Species richness of exotics over time since restoration

Results: Increase in total exotic species richness over time, driven by WT2, PH1, and especially WT1 & RT.

1c. Look at exotic biomass over time

Results: Increase in total exotic species biomass over time, driven by WT1 and especially RT.

1d. Total percent cover of natives over time since restoration

Results: Increase in total native percent cover over time (but peak in years 3-5), driven by WT1, MS, & CS.

1e. Species richness of natives over time since restoration

Results: Decrease in total native species richness over time.

2. What’s driving increase in exotics and decrease in native?

Hypothesis: One exotic is becoming dominant (POMO)

2a. Max percent of exotics over time, max percent of natives over time, by species

Results: Exotic increases largely driven by grasses (UNK GRASS, FEMY, POMO)

Preliminary conclusion: Pools surrounded by houses receive less exotic seed input

2b. Exotic biomass for each pool, by zone

Results:

2c. Percent cover vs. depth of pool

Results: Deeper pools (WT2, TP) have less total exotic percent cover.

3. How does seed bank composition change over time?

Hypothesis: Diversity of natives has increased over time, while diversity of exotics has decreased over time.

3a. Seed Bank Species Abundance

Results: No obvious trends.

3b. Seed Bank Species Richness

Results: Exotic species richness decreases over time. Native species richness also decreases over time.

3c. Compare seed bank species to percent cover species

Results: Exotic species richness decreased from 2016 seed bank. Native species richness decreased from 2016 seed bank. RT and WT1 especially different; differences in seed bank correlate with change in species composition over time.